Prior art bipolar transistors are three-terminal devices that require, in addition to emitter and collector contacts, a base contact. The base contact occupies area on an integrated circuit chip, and processing steps are required to provide the base contact. Clearly, it would be advantageous to have available a bipolar transistor that does not have a separate base contact. Furthermore, it would be advantageous to have available a bipolar transistor that can perform logic tasks that normally require a multiplicity of prior art transistors. This application discloses such a bipolar transistor.
U.S. Pat. No. 4,999,687 discloses a real space transfer (RST) device that can perform logic tasks that normally require a multiplicity of conventional transistors. The structure of an RST device differs from the structure of a bipolar transistor. See also S. Luryi et al., Applied Physics Letters, Vol. 57, p. 1787 (1990).